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A convention can be seen as the standard way of playing a game. If different conventions exist in various geographical, social or other entities (called "towns") and if there is some mobility between these towns, which conventions, if any, will emerge as the successful ones? A simple evolutionary process is suggested and it is shown that the pro...

A convention can be seen as the standard way of playing a game. If different conventions exist in various geographical, social or other entities (called "towns") and if there is some mobility between these towns, which conventions, if any, will emerge as the successful ones? A simple evolutionary process is suggested and it is shown that the process converges to a Nash equilibrium for all games satisfying weak acyclity or a condition called evolutionary stable with respect to pure strategies (ESPS). Further, if the process converges, it converges to an efficient convention for all games in which the Pareto optimal symmetric equilibria are strict. Hence, the paper presents an explanation for the endogenous evolution of efficiency. In contrast to most recent studies in evolutionary game theory, the conclusions do not rely on random "mutations". Instead, the driving force is the tendency of players to have increased interaction with member of their own group (viscosity). Minimize

One of the more convincing interpretations of mixed strategy equilibria describes a mixed equilibrium as a steady state in a large population in which all players use pure strategies but the population as a whole mimics a mixed strategy. To be complete, however, this interpretation requires a good story about how the population arrives at the ap...

One of the more convincing interpretations of mixed strategy equilibria describes a mixed equilibrium as a steady state in a large population in which all players use pure strategies but the population as a whole mimics a mixed strategy. To be complete, however, this interpretation requires a good story about how the population arrives at the appropriate distribution over pure strategies. In this paper I attempt to give an explanation based on an evolutionary, stochastic learning process. Convergence properties of these processes have been studied extensively but almost exclusively for the case of convergence to pure Nash equilibria. Here I study the conditions under which an evolutionary process converges to population mixed-strategy equilibria. I find that not all mixed equilibria can be justified as the result of the evolutionary learning process even if the equilibrium is unique. For symmetric 2x2 and 3x3 games I give necessary and sufficient conditions for convergence and for n*n games I give a sufficient condition. For cases in which the conditions are not satisfied counterexamples are given, in which the process enters a limit cycle. Minimize

This paper addresses the relation between the degree of decentralization in a population and the probability of coordinating on an efficient outcome. An evolutionary learning mechanism with a group structure that allows players to "vote with their feet" is introduced. In contrast to most of the recent literature (e.g. Kandori, Mailath and Rob, 1...

This paper addresses the relation between the degree of decentralization in a population and the probability of coordinating on an efficient outcome. An evolutionary learning mechanism with a group structure that allows players to "vote with their feet" is introduced. In contrast to most of the recent literature (e.g. Kandori, Mailath and Rob, 1993) in which the risk dominant equilibrium is shown to prevail in the long run, in this paper it is demonstrated that given a general probability distribution over initial states the evolutionary learning process converges almost always to the efficient equilibrium if interaction is decentralized enough. Furthermore, it is shown how the model can be applied to the problem of product standardization. Minimize

It is shown that a win-stay, lose-hift behavior rule with endogenous aspiration levels yields cooperation in a certain class of games. The aspiration level in each round equals the current population average. The class of games includes the prisoner's dilemma and Cournot oligopoly and thus yields an explanation for cooperation and collusion. ; c...

It is shown that a win-stay, lose-hift behavior rule with endogenous aspiration levels yields cooperation in a certain class of games. The aspiration level in each round equals the current population average. The class of games includes the prisoner's dilemma and Cournot oligopoly and thus yields an explanation for cooperation and collusion. ; cooperation Minimize

Recently, the theory of informational cascades has been tested in an experiment by Anderson and Holt (1997) who report that their data support the theory amazingly well. In this note we report on an experiment designed to find out whether observed cascades are indeed due to rational Bayesian updating. However, we find little support for rational...

Recently, the theory of informational cascades has been tested in an experiment by Anderson and Holt (1997) who report that their data support the theory amazingly well. In this note we report on an experiment designed to find out whether observed cascades are indeed due to rational Bayesian updating. However, we find little support for rational updating. The simple heuristic "follow your own signal" does much better in explaining our data than Bayesian rationality. ; herding, information cascades, experiments. Minimize

Until June 2000 the European Central Bank (ECB) used fixed rate tenders for its weekly repo auctions. A switch to variable rate tenders became necessary due to massive overbidding by banks. In this paper we introduce a stylized game among banks to investigate this overbidding phenomenon. Our results confirm the weakness of the fixed rate tender ...

Until June 2000 the European Central Bank (ECB) used fixed rate tenders for its weekly repo auctions. A switch to variable rate tenders became necessary due to massive overbidding by banks. In this paper we introduce a stylized game among banks to investigate this overbidding phenomenon. Our results confirm the weakness of the fixed rate tender format and indicate that the ECB's liquidity management has significantly improved since the switch to the variable rate system. Yet recent episodes of rate cut expectations suggest that the ECB's practice of setting a minimum bid rate should be abandoned in favor of a more symmetric interest rate target. Copyright The editors of the "Scandinavian Journal of Economics", 2003 . Minimize

We report results of an internet experiment designed to test the theory of informational cascades in financial markets. More than 6000 subjects, including a subsample of 267 consultants from an international consulting firm, participated in the experiment. As predicted by theory, we find that the presence of a flexible market price prevents herd...

We report results of an internet experiment designed to test the theory of informational cascades in financial markets. More than 6000 subjects, including a subsample of 267 consultants from an international consulting firm, participated in the experiment. As predicted by theory, we find that the presence of a flexible market price prevents herding. However, the presence of contrarian behavior, which can (partly) be rationalized via error models, distorts prices, and even after 20 decisions convergence to the fundamental value is rare. We also study the effects of transaction costs and the expectations of subjects with respect to future prices. Finally, we look at the behavior of various subsamples of our heterogeneous subject pool ; Herding, informational cascades, contrarian behavior, internet experiment Minimize

We provide a new explanation for the apparent underpricing of initial public offerings applicable to large, regulated firms like telecommunications companies. Under the assumption that regulation is subject to political pressure by voters we demonstrate that it may be rational for issuers to ration investors in order to insure a broad distributi...

We provide a new explanation for the apparent underpricing of initial public offerings applicable to large, regulated firms like telecommunications companies. Under the assumption that regulation is subject to political pressure by voters we demonstrate that it may be rational for issuers to ration investors in order to insure a broad distribution of shares in the population. At the same time we explain the common practice of bonus systems designed to prevent investors from taking profits immediately. Minimize

The study of evolutionary dynamics was so far mainly restricted to finite strategy spaces. In this paper we show that this restriction is in most cases unnecessary. We give a mild condition under which the continuous time replicator dynamics are well defined for infinite strategy spaces. Furthermore, we provide conditions for stability of rest p...

The study of evolutionary dynamics was so far mainly restricted to finite strategy spaces. In this paper we show that this restriction is in most cases unnecessary. We give a mild condition under which the continuous time replicator dynamics are well defined for infinite strategy spaces. Furthermore, we provide conditions for stability of rest points. Finally, we apply this general theory to a number of applications like the Nash demand game, the War of Attrition, Cournot and Bertrand oligopoly games, and mixed strategies. ; replicator dynamics, evolutionary stability, continuous strategy spaces, oligopoly Minimize

Experimental results on the ultimatum game show clearly that (1) large fractions of players offer a 'fair' allocation and (2) that unfair (but positive) offers are systematically rejected. We offer an explanation of this behavior using the 'indirect evolutionary approach' which is based on the assumption that players behave rationally for given ...

Experimental results on the ultimatum game show clearly that (1) large fractions of players offer a 'fair' allocation and (2) that unfair (but positive) offers are systematically rejected. We offer an explanation of this behavior using the 'indirect evolutionary approach' which is based on the assumption that players behave rationally for given preferences but that their preferences change through an evolutionary process. We prove that despite anonymous interaction a preference for punishing unfair offers is an evolutionarily successful strategy if players interact in small groups. This leads players to split the resource equally almost always. However, the equal split is not due to 'true fairness' (or 'altruism') but is entirely caused by the (justified) fear that unfair offers might be rejected. ; evolutionary game theory, ultimatum game, punishment. Minimize